HM George I's 10-Great Grandfather. U.S. President [WASHINGTON]'s 12-Great Grandfather. PM Churchill's 17-Great Grandfather. Lady Diana's 17-Great Grandfather. PM Cameron's 18-Great Grandfather. HRH Albert II's 19-Great Grandfather. Louis XVII's 14-Great Grandfather. Poss. Agnes Harris's 14-Great Uncle. `Osawatomie' Brown's 16-Great Grandfather.